Sains Ma1aysiana 27: 61-71 (1998)                                                                                               Sains Bumi/

                                                                                                                                                                Earth Sciences

Groundwater Characteristic of the Chuau River

Basin Selangor, Malaysia

Mohd Nazan Awang

Pengarah Kajibumi Negeri Se1angor & Wilayah Persekutuaan

Tingkat 19, Bangunan Tabung Haji, Jalan Tun Razak 50736, Kuala Lumpur

Muhamad Barzani Gasim

Jabatan Sains Sekitaran, Fakulti Sains Alam Sekitar

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, D.E

Wan Nor Azmin Sulaiman

Jabatan Sains Alam Sekitar, Fakulti Sains Dan Pengajian A1am Sekitar

Universiti Putra Malaysia, 43400 Serdang, Selangor, D.E

ABSTRACT

A new Putrajaya township of Malaysian government administration centre is located in the middle of Chuau River basin. Previously this area was partly covered by a forest reserve, rubber and oil palm plantations, coconut trees, quarries and tin mines. The catchment area which is about 125 km² consists of three main rock formations, i.e. the Hawthornden Schist (older), the Kenny Hill Formation, and the Quaternary deposit (younger). The topography of this area consists of scattered hills and swamps. There is no proper drainage pattern in the study area, and the stream flow is controlled by the season. Quality and quantity of groundwater have been studied from eleven wells in the study area. The depth of each well is between 6 - 7 m (for alluvium) and 60 - 137 m (for rock unit). The total water yield is 1824 m³/ day or equivalent to 0.4 x 10⁶ gallons/day. The water quality analysis shows that groundwater is not suitable for drinking due to its chemical and physical contents, such as mercury (< 0.2 - 2.7 ppm), ferrum (< 0.1 - 10 ppm), silica (8.9 - 56 ppm), hardness (7.5 - 143 ppm), and total dissolved solid (70 - 776 ppm). These values exceed the international standard for drinking water. Finally, groundwater facies classification based on anion and cation contents such as Ca²⁺, Mg²⁺, Na⁺, K⁺, CO₃^2-, HCO₃^-, Cl^- and SO₄^2- , shows that there are at least 2 groups of groundwater facies in the study area, namely: sodium bicarbonate and calcium bicarbonate.

ABSTRAK

Putrajaya adalah pusat pentadbiran Kerajaan Malaysia yang baru, terletak di tengah-tengah lembangan Sungai Chuau. Sebahagian kawasan ini pada mulanya merupakan kawasan hutan simpan, ladang getah, ladang kelapa sawit dan sebahagiannya adalah kawasan lombong timah dan kuari. Kawasan tadahan hujan yang mempunyai keluasan 125 km² dibentuk oleh tiga kumpulan batuan yang utama, iaitu Syis Hawthornden (tertua), Formasi Kenny Hill dan Endapan Kuaterner (termuda). Topografi kawasan terdiri daripada bukit-bukit yang terasing dan kawasan berpaya. Bentuk pola salirannya tidak begitu jelas, dan anak-anak sungainya mengalir mengikut musim. Kualiti dan kuantiti air bawah tanahnya dikaji berdasarkan kepada taburan 11 lubang gerudi yang ada dalam pelbagai batuan dalam kawasan kajian. Kedalaman setiap lubang gerudi adalah diantara 6-7 m (bagi aluvium) dan 60-137 m (bagi batuan). Keupayaan air bawah tanah yang dapat dikeluarkan dalam kawasan kajian ialah sebanyak 1824 m³/ hari atau bersamaan dengan 0.4 x 10⁶ gallon/hari. Hasil analisis secara kimia dan fisikal terhadap aspek kualiti air menunjukkan bahawa air bawah tanah di sini adalah tidak selamat untuk terus diminum, memandangkan terdapatnya kandungan beberapa jenis logam berat yang tinggi dan membahayakan kesihatan, seperti: raksa (< 0.2-2.7 ppm), besi (< 0.1 - 10 ppm), silika (8.9-56 ppm), kekerasan (7.5-143 ppm), kandungan kelodak (70-776 ppm). Kandungan parameter yang disebutkan di atas adalah tinggi dan merbahaya bagi kesihatan, kerana melebihi kandungan piawaian antara bangsa bagi air minuman. Akhirnya, pengkelasan fasies air bawah tanah berdasarkan kandungan kation dan anion, seperti Ca²⁺, Mg²⁺, Na⁺, K⁺, CO₃^2-, HCO₃^-, Cl^- dan SO₄^2- menunjukkan bahawa sekurang-kurangnya terdapat 2 kumpulan fasies utama dalam kawasan kajian, iaitu sodium bikarbonat dan kalsium bikarbonat.

RUJUKAN/REFERENCES

Edmunds, W.M., 1981. Hydrogeochemical investigations. In Lloyd, J.W.(Ed.). Case-studies in groundwater resources evaluation. Oxford, Clarendon Press: 87-112.

Fetter, C.W., 1988. Applied hydrogeology. 2^nd ed.. New York, Macmillan Publishing Company.

Fortescue, J.A., 1979. The role of major and minor elements in the nutrition of plants,          animals and man. In Siegel, F.R. (Ed.) Review of research on modern problems in geochemistry. Paris: UNESCO, 57 - 87

Freeze, R.A., & Cherry, J.A., 1979. Groundwater. Englewood: Prentice Hall, Inc. Gill, I, 1994. Groundwater geochemistry of the Kingshill aquifer system, St. Croix. Environmental Geoscience 1(1): 40-49.

Harvey, J.C., 1982. The properties of groundwater. New York, John Wiley & Sons.

Jones, C. R., 1973. Lower Paleozoic. In Gobbett D. J. Hutchinson, C.S. (Ed.). Geology of Malay Peninsula. New York: John Wiley & Sons.

Kruseman, G.P., & DeRidder, N.A, 1970. Analysis and evaluation of pumping test data. International Institute For Land Reclamation and Improvement, Bulletin 11.

Nasiman, S & Mohd. Nazan, A., 1996. Alluvial aquifer in Selangor: A threatened water resources. Proceeding of Geology and Environment Conference: Auditing and impact. UKM, 6-8 December 1996: 85-101.

Rojas, R., Howard, G., & Bartram, J., 1995. Groundwater quality and water supply in Lima, Peru. In Nash, H. And Mc Call, G.J.H. (Eds.), Groundwater quality. London.Chapman & Hall.    

Rushton, K. R. & Jones, G.P., 1981. Pumping test analyses. In Lloyd, J.W.(Ed). Case studies in groundwater resources evaluation. Oxford: Clarendon Press.

Rump, H. H. & Krist, H., 1992. Laboratory manual for the examination of water, waste water and soil. 2 nd Ed. V.C.H. Weinheim: Verlagsgesellschaft,

Stauffer, P.H., 1973. Kenny Hill Formation. In Gobbett, D.J. and Chutchinson, C.S. (Ed.). Geology of Malay Peninsula. New York: John Wiley & Sons.

Tan, E. H. & Sing, M., 1989. Groundwater supply studies in Northern Kelantan. Geol. Soc Malaysia Bull. 24: 13-26.

Tee, T. P., 1997. Shallow groundwater chemical composition and characteristics for different rock types. B. Sc thesis, Environmental Science Dept., Universiti Putra Malaysia.

Thompson, M.E., 1979. Hydro geochemistry: non - marine unpolluted and polluted waters. In Sigel, F.R.(Ed) Review of research on modem problems in geochemistry. Paris: UNESCO.

US Geological Survey, 1978. Appraisal of shallow groundwater resources and          management alternatives in the Upper Peace and Eastern Alafia River Basin, Florida. Water Resources investigations: 77-124.

US Resources Services, 1981. Groundwater manual. New York: John Wiley & Sons. WHO, 1978. Water quality surveys. Sydenhams Printers.

Watson, I., & Burnett, A. D., 1993. Hydrology: An environmental approach. Cambridge: Buchanan Books.